The present relates to display boards in general and to remotely changing the displayed information on the display boards in particular.
One common form of display utilizes poster displays usually located at strategic road junctions for maximum effect. Such posters are commonly pasted on large display boards and remain for the time period paid for, after which the poster is replaced. A major disadvantage of the poster display is that it is restricted to displaying one poster at a time.
In order to maximize the available net display area, various systems have been developed which allow several, usually not more than three, separate advertisements to be displayed on the same display area. One system uses a rotating screen which contains two advertisements, one of which is visibly displayed at a time.
A second system utilizes a plurality of rotatable triangular slats which allows three separate advertisements to be shown. Each advertisement occupies the whole display area and is cut into strips to enable the slats to be rotated. The slats can be rotated at regular intervals so that each of the three advertisements is consequently displayed.
These existing systems are also limited in that in order to change the one or more of the advertisements, it is necessary to physically replace the poster in situ.
One of the methods for forming an image on a surface is electrophotography. Electrophotography forms a latent image on a photoconductor which is then developed using toner. The toner image is then transferred to a substrate.
Another technique for non-contact printing and imaging is ionography. An example of ionography, by the transfer of electrostatic images on to a dielectric surface using toner, is described in U.S. Pat. No. 5,289,214 to Zur.
Computer controlled display systems are usually based on some kind of projection of an image. The practical solutions, due to the limited power of the lamp are such that the image cannot be seen with a good contrast in outdoor applications, due to the high brightness of the ambient sunlight.
This invention works in reflection mode like the classical poster display, that is it uses the ambient light as light source.
An object of the present invention is to provide a display system that can be remotely changed, so that different images are successively displayed with minimal interruption.
A further object of the present invention is to utilize ionography techniques for non-contact printing and imaging for display. Thus by exploiting electrostatic imaging techniques, an advertisement can be displayed promptly by transferring a toner image onto an imaging belt.
A further object of the present invention is to provide a display board that can be used both during daylight and at night.
There is thus provided, in accordance with a preferred embodiment of the present invention, a display system which includes at least one display screen, printing means for transferring color images on to the at least one display screen, erasing means for erasing the color images from the at least one display screen and drive means connected to the at least one display screen for operatingly moving the at least one display screen.
Furthermore, in accordance with a preferred embodiment of the present invention, the drive means moves the at least one display screen from a first printing position to a second viewing position.
In addition, in accordance with a preferred embodiment of the present invention, the system according to claim 1 further includes an interface control unit coupled to at least the at least one display screen and processing means communicating with the interface control unit to control the display of the images.
Furthermore, in accordance with a preferred embodiment of the present invention, the display screen includes a plurality of display screens, each of which displays a separate color separation of the image.
In addition, in accordance with a preferred embodiment of the present invention, the system also includes a dual purpose screen having a substantially white reflective diffusing portion and a substantially transparent portion and a substantially transparent protective screen placed in front of the at least one display screen. Each of the plurality of display screens includes an endless dielectric imaging belt.
Furthermore, in accordance with a preferred embodiment of the present invention, each of the separate color separation images is a digitized version for one of each of the three color separations of cyan, magenta and yellow (C, M and Y).
In addition, in accordance with a preferred embodiment of the present invention, the printing means includes a separate toner reservoir for each of the separate color separation images and writing means for applying toner from each of the separate toner reservoirs onto each of the at least one display screen.
Furthermore, in accordance with a preferred embodiment of the present invention, the erasing means includes static eliminators for cleaning and erasing the toner from the at least one display screen and at least one receptacle for the at least one display screen for receiving and storing the removed toner. The static eliminators comprise one of a group of eliminators including active hot static eliminators; active shockless static eliminators and passive static eliminators.
Furthermore, in accordance with a preferred embodiment of the present invention, the system further includes pumping means to transfer toner from each of the at least one receptacles to the corresponding toner reservoir.
In addition, in accordance with a preferred embodiment of the present invention, the drive means is connected to the dual purpose screen for operatingly moving the dual purpose screen from a first position wherein the substantially white reflective diffusing portion is placed behind the at least one display screen to a second position wherein the substantially transparent portion is placed behind the at least one display screen.
Additionally, there is provided a display system which includes a single display screen and a plurality of printing arrangements located adjacent it, each printing arrangement for each of base colors.
Furthermore, in accordance with a preferred embodiment of the present invention, the interface control unit is coupled to the drive means.
The system further includes a roller track for supporting the writing means thereby to allow the writing means to be moved longitudinally along the track. The roller track further supports the erasing means thereby to allow the erasing means to be moved longitudinally along the track.
Furthermore, in accordance with a preferred embodiment of the present invention, the movement of the printing means and erasing means is controlled by the interface and control unit.
Additionally, there is provided, in accordance with a preferred embodiment of the present invention, a method for producing at least one display image onto a screen The method includes the steps of:
preparing the at least one display image;
communicating the at least one display image to an interface and control unit;
printing the prepared at least one display image on to at least one display screen; and
moving the at least one display screen into position for viewing.
Furthermore, in accordance with a preferred embodiment of the present invention, the method further includes the step of erasing the displayed image and also includes the steps of:
preparing a replacement display image; and
communicating the replacement display image to the interface and control unit.
In addition, in accordance with a preferred embodiment of the present invention, the method further includes the step of concurrently printing the replacement display image while the first displayed image is being erased, the step of printing the replacement display image on a separate part of the at least one display screen while the first image is being displayed and the step of erasing an image and concurrently printing a replacement display image on a separate part of the at least one display screen while another image is being displayed.
Alternatively, the method may comprise the step of depositing base colors images to a single display screen concurrently.
Furthermore, in accordance with a preferred embodiment of the present invention, the method further includes the step of moving a dual purpose screen having a substantially white reflective diffusing portion and a substantially transparent portion behind the at least one display screen. Moving includes the step of activating the dual purpose screen to move the substantially transparent portion behind the at least one display screen whenever the amount of light falls below a pre-determined level.
In addition, in accordance with a preferred embodiment of the present invention, the printing step includes the steps of:
storing toner for each of the separate color separation images in separate reservoirs; and
applying toner from each of the separate toner reservoirs onto each of the corresponding plurality of display screens.
Finally, the step of erasing the displayed image includes the steps of removing the toner from each of the plurality of display screens and storing the removed toner for reuse in the separate toner reservoirs.